Mine anchor-line cutter with flare

ABSTRACT

1. The combination with a mine anchor-line cutter having an anvil and an explosively driven chisel, of a buoyant flare, a flare holder, and a band extending around the holder and the anvil in the path of the chisel where the band will be cut when the cutter is fired under water to sever an anchor-line, whereby the flare will be released, the flare containing a chemical adapted when moistened to generate gas that will produce a flame on reaching the surface of the water.

I United States Patent 1191 1111 3,850,075

Temple Nov. 26, 1974 MINE ANCHOR-LINE CUTTER WITH 2,744,291 5/1956 Stastny et a1. 18/48 s FLARE 2,787,809 4 1957 Stastny 18/48 s 2,791,785 5/1957 Metts .1 9/9 [75] Inventor: Robert Temple, Swissvale, Pa.

73] A M S f t A r C OTHER PUBLICATIONS xi g; lances ompany A Manual of Plastics and Resins, edited by Wm. Schack, Chemical Publishing C'o., Inc., Brooklyn, [22] Filed: June 14, 1956 N.Y., Copyright 1950, pp. 172 and 173.

[21] Appl. No.: 591,368

Primary Examiner-R0bert F. Stalhl Attorney, Agent, or Firm-Brown, Murray, Flick & [52] US. Cl. 89/1 B, 114/221 A peckham [51] Int. Cl. B63g 7/02 [58] Field of Search 102/1 M, 7, 37.8; 89/1.01;

114/221, 221.1; 9/9, 8.3; 18/48 s, 45; 260/669 EXEMPLARY CLAIM l. The combination with a mine anchor-line cutter [56] References Cit d having an anvil and an explosively driven chisel, of 21 UNITED STATES PATENTS buoyant flare, a flare 1101(161', and a band extending 2 H9 697 6 1938 A d 102 7 around the holder and the anvil in the path of the 2372695 441945 z 8/48/S chisel where the band will be cut when the cutter is 2420987 5/1947 z 01 UX fired under water to sever an anchor-line, whereby the 2:422:506 6 1947 rem leiifiunuuu. 5.1,, 89/1i01 UX flare will be released, the flare Containing a Chemical 2,451,121 10 1948 Schermuly et a1. 102 7 adapted when moistened to generate gas that will pro- 2,543,079 2/ 1951 Veek 102/7 X duce a flame on reaching the surface of the water. 2,723,404 11/1955 Krantz. 9/9 2,736,044 2/1956 Lewis 9/83 3 Clams 9 Drawmg Flgures a4 a9 a2 \83 MINE ANCHOR-LINE CUTTER WITH FLARE This invention relates to the cutting of the lines by which explosive mines are anchored in bodies of water, and more particularly to cutting tools for that purpose equipped with signal flares.

Explosively actuated mine anchor-line cutters are well known and have taken several different forms. A typical tool is shown in my US. Pat. No. 2,422,506. Such tools are carried by sweep lines that extend outward and backward from opposite sides of a ship, with several tools on each line. When several mine sweepers are operating in a group, there is always the danger of a mine which has been cut loose by one ship being run into by another ship in the group with disastrous results. This danger is increased greatly when sweeping is done at night, because it often is difficult to see a freed mine after it has risen to the surface of the water.

It is among the objects of this invention to provide for signaling the location of a freed mine the moment it rises to the surface, and to provide a flare which will be carried by the anchor-line cutter and released when the cutter is fired and which will automatically burst into flame when it rises to the surface of the water.

In accordance with this invention, a buoyant flare is connected to a mine anchor-line cutter in such a way that when the cutter is tired to cut an anchor-line, the flare will be released from the cutter at the same instant and will rise to the surface where it will immediately produce a flame that will signal the presence of the freed mine.

The invention is illustrated in the accompanying drawings, in which FIG. 1 is a fragmentary plan view of the cutting end of a mine anchor-line cutter provided with a flare;

FIG. 2 is an enlarged fragmentary front view of the cutter, showing the flare partly broken away in section;

FIG. 3 illustrates a released flare floating on a body of water and producing flames;

FIG. 4 is a fragmentary horizontal section through a modified cutter and flare;

FIG. 5 is a front view thereof;

FIG. 6 shows the flare floating on water and produc ing flames;

FIG. 7 is a fragmentary plan view of another modification;

FIG. 8 is a front view thereof, partly in section; and

FIG. 9 is an axial section through a special cutting chisel that can be used with an anchor-line cutter, with a flare inside of the chisel.

Referring to FIGS. 1 and 2 of the drawings, a stabilizing fin 1 has its longitudinal axis extending in the direction in which the cutter is pulled through the water by a sweep line 2 extending backward and laterally from a mine sweeper (not shown) in a well-known manner. The front edge of the fin is inclined to its longitudinal axis to the same degree as the sweep line. This front edge is provided at its opposite ends with integral ears 3 that hook over the sweep line. Bolt 6, extending through the fin and each ear, holds the tin on the sweep line.

Rigidly mounted on the front portion of the fin is the metal frame 10 of the cutting tool. The longitudinal axis of the frame extends across the fin, and the frame is set back from the front corner of the fin so that only a small amount of the frame extends across the inclined front edge of the fin. The front side of this outwardly projecting portion of the frame is provided with a recess 1 1 that extends lengthwise of the frame. The frame also is provided with a longitudinal bore extending inwardly from the inner end of the recess, and this bore normally contains a cutting chisel 12 that is held in retracted position by a shear pin 13 extending through. it and the surrounding frame.

The end of the frame beside the recess is provided with a slot 14 for receiving a tongue 15 on one end of a guide member 16. The tongue and frame are provided with aligned transverse passages, through which a shear pin 17 extends. The guide member 16 extends across the end of recess 11 to form an anvil 18, and then the guide turns and extends along the front side of the recess toward the chisel. At a point spaced from the chisel, the guide is inclined forward away from the frame to form a finger 19 that will intercept a mine anchor-line and direct it into the cutting notch formed by recess 11 between the guide and frame.

When a mine anchor-line 21, across which the sweep line and fin have been dragged, is caught in the cutting notch, it is cut by the chisel which is driven against it by the force of an explosion from a cartridge (not shown) removably mounted in the frame at the inner or rear end of the chisel. During cutting, the mine line is backed up by the front and back walls of the cutting notch, and by the anvil 18 in the path of the chisel. To explode the cartridge, a firing mechanism is mounted in the inner end of the frame. This mechanism forms no part of this invention and is not shown, but it can be seen in US. Pat. No. 2,422,506. It includes a plunger 38 slidably mounted in a guiding slot 39 extending lengthwise of the back side of the frame. Connected to the rear end of the plunger is a rod 42 that is slidably mounted in a bore through a block 43 rigidly mounted in slot 39 behind the cutting notch. The plunger is urged toward the inner end of the frame by a coil spring 44 encircling the rod and compressed between the plunger and block 43. The plunger normally is held in retracted position, with the spring compressed, by means of a trip pin 46 of small diameter extending through. guide member 16, across the cutting notch, through the frame and into a transverse opening 47 in the plunger rod.

When a mine anchorline 21 enters the cutting notch, it engages the trip pin 46, the front end of which is held in fixed position by engagement of its head with guide member 16. As the anchor-line bends the pin toward anvil 18, the rear end of the pin is pulled out of the plunger rod, thereby releasing the plunger. The released plunger actuates the firing mechanism, as described in detail in said patent, and the cartridge is detonated. The force of the explosion builds up until it is sufficient to cause the cutting chisel to shear off pin 13. The chisel then shoots forward, and in cutting the anchor-line it also shears off the portion of trip pin 46 in the cutting notch. Shear pin 17, which connects guide member 16 to the frame, is strong enough to hold the anvil in place until the chisel has severed the anchorline. The impact of the chisel against the anvil then causes the tongue 15 of guide member 16 to shear off pin 17 and slide out of frame slot 14. Release and loss of the guide member in this manner is justified because, otherwise, the next mine anchor-line might catchin the cutting notch, where it would not be cut.

As soon as a mine anchor-line is cut, the mine that is thereby released rises to the surface of the water and floats there until detonated in some suitable manner. It is a feature of this invention that the presence of the mine floating on the water is clearly indicated at night when the mine otherwise might not be seen. Accordingly, a buoyant flare is carried by the cutter in such a manner that it will be released when the cutter is fired and will rise to the surface with the mine, where it will immediately burst into flame and serve as a beacon.

The flare shown in FIGS. 1, 2 and 3 includes a ball 50 of buoyant material, preferably cork. This ball has a diametrical passage through it, the size of which is reduced at one end. Mounted in this passage is a lightweight metal tube 51 having a reduced end that fits in the reduced end of the passage to hold the tube in place. The other end of the tube projects from the ball to form a weight that will cause the ball to float with the projecting end of the tube down, as shown in FIG. 3. Disposed in the larger portion of the tube is the chemical 52 that produces the flame. This chemical is calcium phosphide, which may also contain calcium carbide. When such a chemical becomes wet, it immediately generates a gas. The calcium phosphide gas will burst into flame in the presence of oxygen, but the calsium carbide gas must be ignited by the first gas. The calcium carbide is used in order to provide a bright, steady signal flame, because calcium phosphide gas produces an intermittent flame that is not very bright. To keep the chemical dry until it is to be used, it is tightly sealed in a frangible receptacle, such as a glass bottle 53. The bottle is held in the metal tube by turning in the outer end of the tube.

In order to attach this flare to the cutter, preferably to its anvil 18, the outer side of the anvil is provided with a spherical recess 55 for receiving part of the buoyant ball, and with a bore 56 for receiving the projecting end of tube 51. The exposed major portion of the ball is held in a metal cup 57, the open side of which fits around a cylindrical projection 58 on the anvil. The circular edge of the cup is soldered at 59 to a shoulder 60 extending around the projection. The side wall of the cup preferably is provided with parallel slots 61 extending inward from its edge.

When the cutter is fired, the chisel 12 is driven through 'a mine anchor-line in the cutting notch and against the anvil with tremendous force. The shock of this impact easily breaks the soldered joint 59 between the flare cup and the anvil, and it also causes the segments of the cup between its parallel slots to flare out. The cup immediately separates from the anvil and releases the flare, which quickly rises to the surface of the water, reaching there at about the same moment as the freed mine. The shock that broke the cup away from the anvil also shatters the glass bottle in the cork ball, so the chemical 52 becomes wet with sea water and generates gas which bursts into flame as soon as the flare reaches the air. The flames 62 (FIG. 3) shooting off the flare show clearly that a mine has come to the surface, and they mark its location. The chemical does not leave the tube because it is held in a porous fabric bag 63, which may be either inside or outside of the bottle before tha bottle is 'ulverized by the cutting shock.

It has been observed in practice that the gas which is generaged under water by the flare reaches the surface of the water at the same time as the flare. Consequently, gas can be generated in the flame at the surface of the water is determined by the depth at which the flare is released from the mine anchor-line cutter.

If anvil 18 is accidentally released from the cutter without the cutter being fired, the flare will not be released from the anvil to provide an erroneous signal. This is due, of course, to the fact that the chisel has not been driven against the anvil to break the bottle containing the flare chemical.

In the modified embodiment of the invention disclosed in FIGS. 4, 5 and 6, the outer side of the anvil 65 connected to the cutter frame 66 is provided with a semi-cylindrical recess 67 extending lengthwise of the anvil. Spidered to the opposite edges of this recess by a joint 68 is a semi-cylindrical member 69 which forms with the recess a cylindrical chamber 70. This chamber contains a flare which is held in place by the lug 71 projecting from the anvil at one end of the chamber and by a retaining gin 72 extending across the opposite end of the recess. This particular flare includes a frangible receptacle, such as a glass bottle 73, in which the flame-producing chemical 74 is sealed. The chemical is contained in a metal tube 75 that is enclosed by a fabric bag 76. The tube is in the center of the bottle and is encircled by a cylindrical float 77, most suitably formed from polystyrene. The float is produced by pouring a predetermined amount of polystyrene beads into the bottle before the tube is inserted, then inserting the filled tube and bag, and then heating the bottle as it is rolled back and forth. The heat causes the beads to swell greatly and fill the space around the tube as they adhere to one another to form a unitary buoyandy cylinder. I

When the cutter is fired in order to cut a mine anchor-line,.the impact of the cutting chisel against the anvil breaks the soldered joint 68 between the flare holder 69 and the anvil, and simultaneously shatters the glass bottle. Consequently, the buoyant float is released from the anvil and also from the bottle and quickly rises to the surface of the water, where the gas that is generated by the wet chemical ignites and produces flames 78 (FIG. 6) that issue from the opposite ends of the floating flare.

The cutter anvil 80 shown in FIGS. 7 and 8 has its same shape as the one just described, and a similar semi-cylindrical flare holder 81 is used. However, instead of soldering the holder to the anvil, it is strapped to it by a metal band 82 that extends around the holder in a groove 83 and across the top and bottom of the anvil. The ends of the band are connected by a cross member, such as coil spring 84, extending across the inner face of the anvil. To prevent the holder from sliding around on the anvil, it is pinned to it by a pair of dowl pins 85 at the opposite edges of the holder. The flare is like the one shown in FIG. 4 and is held in the holder in the same way by a lug 86 and a retaining pin 87. When the cutter is fired, the chisel will sever spring 84 and thereby release the flare holder from the anvil. Since the bottle 88 is shatteredat the same instant, the buoyant flare 89 floats to the surface.

Instead of connecting the flare to the cutter frame or anvil, a special cutting chisel may be provided which will contain the flares. Thus, as shown in FIG. 9, such a chisel 91 is provided with an axial bore 92 extending forward from its rear end. Inside of this bore is a buoyant flare 93, similar to the one shown in FIG. 4, but of smaller diameter. The flare is normally held in the chisel by a closure disc 94 soldered at 95 to the rear end of the chisel. When the cutter is fired, the shock of the explosion will break the solder joint 95 and shatter the flare bottle so that the buoyant flare can escape from the rear end of the chisel that sinks through the water. To insure rapid release of the flare from the chisel, it is preferably positively ejected therefrom. Thus, a coil spring 96 may be compressed between the front end of a reduced axial bore 97 in the chisel and a disc 98 engaging the front end of the flare. When closure 94 separates from the chisel, this coil spring quickly ejects the flare from the chisel.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment, However, I desire to have it understood that, within the scope of the appended duce a flame on reaching the surface of the water.

2. A mine anchor-line cutter comprising an anvil, a chisel adapted to be driven forward under water against the anvil by the force of an explosion behind the chisel to sever an anchor-line, the chisel being provided with an axial bore extending forward from its rear end, a closure for the rear end of the bore, a solderjoint connecting the closure to the chisel and a buoyant flare in said bore, said solder joint being adapted to be broken by the force of the explosion to release said closure from the chisel, whereby the chisel will be opened for escape of the flare, said flare containing a chemical that will produce a flame on reaching the surface of the water.

3. A mine anchor-line cutter comprising an anvil, a chisel adapted to be driven forward under water against the anvil, by the force of an explosion behind the chisel to sever an anchor-line, the chisel being provided with an axial bore extending forward from its rear end, a closure for the rear end of the bore, a solderjoint connecting the closure to the chisel, a buoyant flare in said bore, and a coil sping compressed between the front end of the flare and the chisel and pressing the flare tightly against the closure said solder joint being adapted to be broken by the force of the explosion, whereby the flare will be ejected from the chisel by said spring, said flare containing a chemical that will produce a flame on reaching the surface of the water.

=l l l 5 

1. The combination with a mine anchor-line cutter having an anvil and an explosively driven chisel, of a buoyant flare, a flare holder, and a band extending around the holder and the anvil in the path of the chisel where the band will be cut when the cutter is fired under water to sever an anchor-line, whereby the flare will be released, the flare containing a chemical adapted when moistened to generate gas that will produce a flame on reaching the surface of the water.
 2. A mine anchor-line cutter comprising an anvil, a chisel adapted to be driven forward under water against the anvil by the force of an explosion behind the chisel to sever an anchor-line, the chisel being provided with an axial bore extending forward from its rear end, a closure for the rear end of the bore, a solder joint connecting the closure to the chisel, and a buoyant flare in said bore, said solder joint being adapted to be broken by the force of the explosion to release said closure from the chisel, whereby the chisel will be opened for escape of the flare, said flare containing a chemical that will produce a flame on reaching the surface of the water.
 3. A mine anchor-line cutter comprising an anvil, a chisel adapted to be driven forward under water against the anvil by the force of an explosion behind the chisel to sever an anchor-line, the chisel being provided with an axial bore extending forward from its rear end, a closure for the rear end of the bore, a solder joint connecting the closure to the chisel, a buoyant flare in said bore, and a coil spring compressed between the front end of the flare and the chisel and pressing the flare tightly against the closure, said solder joint being adapted to be broken by the force of the explosion, whereby the flare will be ejected from the chisel by said spring, said flare containing a chemical that will produce a flame on reaching the surface of the water. 